This invention relates to electrical combiner/splitter systems and more specifically to tri-phase combiner/splitter systems for high power amplifier applications.
Numerous modern day applications require power levels that greatly exceed the capability of commercially available individual devices. Common practice by those skilled in the art is to couple a plurality of devices in a network fashion thereby yielding the desired output. Typically, the input power is split and delivered to several devices via a dividing network. The output power of these devices is collected via a combining network to generate a larger output power level. Such a system is often referred to as an n-way amplifier, where n represents the number of amplifier devices utilized in the network. By using combiner/splitter networks, an n-way amplifier can be built from n individual amplifiers to obtain a theoretical output of n times the output power of the individual amplifiers in the system.
Two popular combiner/splitter networks are the chain and corporate structures. The chain structure resembles a collection of devices coupled in cascade fashion. The chain structure offers the advantage of ease of changing the number of ports in the network. To add a port to an existing structure, a coupler having a predetermined coupling coefficient is added to the chain with all other couplers remaining unchanged. A limitation of the chain structure is the difficulty of building couplers having high coupling coefficients when large numbers of sources are combined. Some couplings are too weak for branch-line couplers or split-T couplers and some are too strong for parallel line couplers. The corporate structure is not as flexible as the chain structure and generally resembles a combination of numerous outputs converging into a single device output. The corporate structure usually offers less coupling loss and hence higher efficiency as the number of combining sources increases than the chain structure.
There exists a need for a combiner/splitter network having components and configuration that yield favorable output for wideband operations.